NAME

srec_aomf - Intel Absolute Object Module Format

DESCRIPTION

The Absolute Object Module Format (AOMF) is a subset of the 8051 OMF.
The structure of an absolute object file (the order of the records in
it) is similar to that of a relocatable object file. There are three
main differences: the first is that an absolute object file contains
one module only, the second is that not all the records can appear in
the absolute file and the third is that the records can contain only
absolute information.
GenericRecordFormat
Each record starts with a record type which indicates the type of the
record, and record length which contain the number of bytes in the
record exclusive of the first two fields. The record ends with a
checksum byte which contains the 2s complement of the sum (modulo 256)
of all other bytes in the record. Therefore the sum (modulo 256) of
all bytes in the record is zero.
The record length includes the payload and checksum fields, but
excludes the type and length fields.
All 16-bit fields are little-endian.
+-----+----------+------------------+------+
|REC | Record | Payload | CHK |
|TYP | Length | | SUM |
|8 | 16 bits | | 8 |
|bits | | | bits |
+-----+----------+------------------+------+
Here are some of the relevant record types:
0x01 Scope Definition Record
0x02 Module Start Record
0x04 Module End Record
0x06 Content Record
0x0E Segment Definition Record
0x12 Debug Items Record
0x16 Public Definition Record
0x18 External Definition Record
Names are not stored a C strings. Names are stored as a length byte
followed by the contents.
Structure
An AOMF file consists of a module header record (0x02), followed by one
or more content (0x06), scope (0x01) or debug (0x12) records, and ends
in a module end record (0x04).
The records with the following types are extraneous (they may appear in
the file but are ignored): 0x0E, 0x16 and 0x18 (definition records).
All records which are not part of the AOMF and are not extraneous are
considered erroneous.
ModuleHeaderRecord
+-----+----------+--------------+------+------+------+
|REC | Record | Module Name | TRN | zero | CHK |
|TYP | Length | | ID | 8 | SUM |
|0x02 | 16 bits | | 8 | bits | 8 |
| | | | bits | | bits |
+-----+----------+--------------+------+------+------+
Each module must starts with a module header record. It is used to
identify the module for the RL51 and other future processors of 8051
object files. In addition to the Module Name the record contains:
TRN ID The byte identifies the program which has generated this
module:
0xFD ASM51
0xFE PL/M-51
0xFF RL51.
ModuleEndRecord
+-----+----------+--------------+----------+------+------+------+
|REC | Record | Module Name | zero | REG | zero | CHK |
|TYP | Length | | 16 bits | MSK | 8 | SUM |
|0x04 | 16 bits | | | 8 | bits | 8 |
| | | | | bits | | bits |
+-----+----------+--------------+----------+------+------+------+
The record ends the module sequence and contains the following
information: characteristics
MODULE NAME
The name of the module is given here for a consistency check.
It must match the name given in the Module Header Record.
REGISTER MASK (REG MSK)
The field contains a bit for each of the four register banks.
Each bit, when set specifies that the corresponding bank is
used by the module:
Bit 0 (the least significant bit)
bank #0.
Bit 1 bank #1.
Bit 2 bank #2.
Bit 3 bank #3.
ContentRecord
+-----+----------+------+----------+--------------+------+
|REC | Record | SEG | Offset | DATA | CHK |
|TYP | Length | ID | 16 bits | | SUM |
|0x06 | 16 bits | 8 | | | 8 |
| | | bits | | | bits |
+-----+----------+------+----------+--------------+------+
This record provides one or more bytes of contiguous data, from which a
portion of a memory image may be constructed.
SEG ID This field must be zero.
OFFSET Gives the absolute address of the first byte of data in the
record, within the CODE address space.
DATA A sequence of data bytes to be loaded from OFFSET to
OFFSET+RECORDLENGTH-5.
SizeMultiplier
In general, raw binary data will expand in sized by approximately 1.02
times when represented with this format.

SOURCE

COPYRIGHT

srec_cat version 1.39
Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
2007, 2008 Peter Miller
The srec_cat program comes with ABSOLUTELY NO WARRANTY; for details use
the ’srec_cat-VERSionLicense’ command. This is free software and you
are welcome to redistribute it under certain conditions; for details
use the ’srec_cat-VERSionLicense’ command.